Cumulative Layout Shift (CLS)
CLS measures total unexpected layout shift throughout a page's lifetime. Layout shift occurs when elements change position without user interaction. Good threshold: ≤0.1, needs improvement: 0.1-0.25, poor: >0.25.
⚡Why It Matters
Layout shifts frustrate users — especially when reading or clicking. Images without dimensions, injected ads, and late-loading fonts are common causes.
🔍How AiSEO Checks
AiSEO measures CLS via PageSpeed and CrUX, identifies elements causing the largest layout shifts, and suggests adding width/height to images and reserving ad space.